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B-738 Crash in Russia Rostov-on-Don

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B-738 Crash in Russia Rostov-on-Don

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Old 24th Mar 2016, 20:42
  #621 (permalink)  
 
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3500 feet per minute at 1000 AGL on both. The plane is already flying. It's not an emergency. Why fly like that? I don't care what the flight director says. Yet time and time again you see guys doing this on a miss. Guaranteed setup for a low energy state.
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Old 24th Mar 2016, 20:51
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Originally Posted by PKPF68-77
Icing & the Rostov upper air ascent.

I find the upper air sounding for Rostov for 00Z 19 March 2016 shows the following:

1: Air temperature 0C at 2000-3000ft falling to -10C by 12000ft and -27C at 17000ft.
2: Saturated air, without a break, between about 2000-3000 ft and 17000ft.
3: Air mass stable wrt to saturated air between about 3000 ft and 17000 ft - hence no Cb, but suggestive of thick multilayer cloud, common in frontal zones.


Area of doubt.
As was the case over 50 years ago when I first plotted tephigrams, it seems that even today, the humidity sensors used by different nations behave differently.

Rarely in the UK did we see ascents showing saturated air, without a break, up to great altitudes.
This Rostov ascent shows temperatures and dew points very close together, even above the tropopause! I cannot 100% say that the dew point readings are wrong, but they do appear most anomalous. Sometimes it appears that once the humidity sensor gets a soaking in the lower levels, it may not dry out properly to give accurate readings higher up.
Maybe more up to date meteorologists may like to comment.
Absolutely, it's not a realistic sounding for dew point/humidity. Obviously the humidity sensor remained frozen/iced over during the entire ascent. There was quite some water in the air, but again: Nothing that wouldn't be seen a dozen of times in Scotland, Iceland or else during a winter.

Last edited by weatherdude; 24th Mar 2016 at 20:56. Reason: typo
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Old 24th Mar 2016, 21:28
  #623 (permalink)  
 
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And flight directors don't care about wonky high unsustainable pitch attitudes when flying into strong increasing headwinds. I believe this will be a factor.
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Old 24th Mar 2016, 21:47
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737er And flight directors don't care about wonky high unsustainable pitch attitudes when flying into strong increasing headwinds. I believe this will be a factor.
Wow FD will command a 15 degrees pitch up during a GA. I never knew that was wonky, high and unsustainable. Thanks for sharing your valuable insight.
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Old 24th Mar 2016, 21:55
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Boeing source just confirmed the FD in a wind shear warning will guide you through the mcp altitude.
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Old 24th Mar 2016, 21:55
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THS tricks

Originally Posted by Chesty Morgan
Not really true. Even with total hydraulic failure it's possible to control the aircraft with a stab trim out by more than 23 turns. Ask me how I know.

How? Manual trim wheel?
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Old 24th Mar 2016, 21:59
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Does FZ have a FOQA program?
Any rumours om ACARS transmits?
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Old 24th Mar 2016, 22:20
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Deep Stall

Just for info. Check this video of a deep stall in the 737.

https://www.youtube.com/watch?v=kkYXhLwlHrg
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Old 24th Mar 2016, 22:23
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Holding like this happens every day.
Nothing new, mid 1960's, a Friday night Nassau - New York, starting holding over Baltimore and eventually landed over 2 hours later, a common occurrence in those days, not a weather issue but the volume of 'traffic' approaching New York. 'course we had been warned and carried the fuel.
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Old 24th Mar 2016, 22:53
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You are welcome PT6Driver. Except you are only a little bit right.




Pitch Modes
•TO/GA – Takeoff Engaged for takeoff by turning both F/D switches ON and pushing either TO/GA switch. Both F/Ds must be ON to engage TO/GA prior to starting takeoff.
The AFDS commands pitch attitude in the following order:
•10 degrees nose down until 60 knots IAS
•15 degrees nose up after 60 knots IAS
•15 degrees nose up after lift–off until a sufficient climb rate is acquired.
Then, pitch is commanded to maintain MCP speed plus 20 knots.TO/GA can also be engaged for takeoff with F/D switches OFF if a TO/GA switch is pushed after 80 knots IAS below 2000 feet AGL and prior to 150 seconds after lift–off.
What happens in weather conditions like this where the wind is a violently strong and gusty rapidly increasing headwind is the FD directs pitch for MCP speed plus 20 and at go around thrust this will command a pitch attitude that is unsustainable once the increasing headwind goes away...and it will.

15 degrees is good and you don't need that much. Where pilots bone this up is following a FD up to oblivion. The FD simply can't keep up with the dynamics involved. The answer is 15 degrees as long as you have a good climb going and if max flap speed become a problem pull the damn power back.

Everyone is gonna have to face it. We have to know how to fly. Automation isn't always good to us. It's a great tool used appropriately.
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Old 24th Mar 2016, 23:11
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Threemiles?

Where did the information in your graphs come from?

If I am reading the second GA graph correctly, they went from a positive 4,000 FPM climb to a negative 15,000 FPM in about 6 seconds.

That is a huge change.
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Old 24th Mar 2016, 23:31
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If not a catastrophic flight control failure(HS/rudder),then maybe engine failure below Vmca has to be considered.The scenario is nicely set for a Vmca encounter;low weight,aft cg,high thrust,windshear,pilots trained to follow FD like pavlov dog.
This also explains the 18500fpm dive.
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Old 25th Mar 2016, 00:17
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Originally Posted by Old Boeing Driver
Where did the information in your graphs come from?

If I am reading the second GA graph correctly, they went from a positive 4,000 FPM climb to a negative 15,000 FPM in about 6 seconds.

That is a huge change.
FR24 on their blog site.
I haven't depicted GS because I think it is misleading.
Low energy state seems to me to be the right description at least. But that's certainly not enough to let it drop like this. It needs more cheese holes.
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Old 25th Mar 2016, 00:37
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Originally Posted by DaveReidUK
Airspeed isn't one of the parameters captured by FR24 in this instance.

As a proxy, the groundspeed at impact-10s (the point at which the aircraft stops climbing) is around 185kts.
The last plot is not the impact, but at 700 ft AGL. This may be due to ADS-B reception limitation or aircraft disintegration.

The Go Around starts at 800 ft AGL/1100 ft MSL. The Missed Approach Altitude is 2240 ft MSL. From RT it seems their intention was to climb to FL80, though they never got a clearance for that.
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Old 25th Mar 2016, 01:20
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I thought they did get a clearance to FL080?

Last edited by jfkjohan; 25th Mar 2016 at 01:20. Reason: Grammar
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Old 25th Mar 2016, 01:28
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Just to add to my heavy handed rant from my perch....I'm in no way implying these gents weren't good sticks and in fact my preach could very well be preaching to the choir with regards to these guys.

If their rumored rosters are correct then I think fatigue will also be a serious factor on this one especially considering how their day way going. Lots of stuff going on when you are holding for bad weather and getting close to bingo fuel. Like someone else posted, math you can normally do in your head all of a sudden requires a calculator and tests show it has as a serious effect as being drunk. Reflexes slow. Instrument scan slows markedly. Stuff you do almost reflexively when well rested requires pause and much extra thought. Fighting off tunnel vision becomes a personal war.

These guys might have been top notch dudes in every way. They might have done exactly what they were trained to do in this circumstance, even if that training wasn't optimum. I'm going to assume they were great pilots until something proves it to me otherwise and for me fatigue and training will most definitely be factored in that mix. I hope it is for the investigation as well.
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Old 25th Mar 2016, 01:30
  #637 (permalink)  
 
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I thought they did get a clearance to FL080?
They did. And they informed ATC that's what they intended to do if they missed, ahead of time while still on approach.
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Old 25th Mar 2016, 04:10
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Unhappy

"And to nail my views to the door of the cathedral (as it were), nowhere does it say in my manual that WS system disables the altitude capture. And why should it? You are supposed to dial in the MA altitude, which should take MSA into account. And you don't want to fly up into an upper airway that might be very busy, so why bust that preset altitude? I have done this several times, and I am sure on each occasion altitude was captured."

or

"Boeing source just confirmed the FD in a wind shear warning will guide you through the mcp altitude."

Well at least thats settled then...

Last edited by CodyBlade; 25th Mar 2016 at 08:10.
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Old 25th Mar 2016, 06:09
  #639 (permalink)  
 
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737er

15 degrees is good and you don't need that much. Where pilots bone this up is following a FD up to oblivion.
.. You've done it now, you've mentioned an attitude and even worse mentioned ignoring the FD.

Go and wash your mouth out with soapy water, wipe your keyboard clean and don't come back until you've learnt that it is far more important these days to discuss and nitpick modes ad -infinitum........

ATB
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Old 25th Mar 2016, 08:18
  #640 (permalink)  
 
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Originally Posted by threemiles
The last plot is not the impact, but at 700 ft AGL.
Well yes, given that the ROD at that point was approaching 20,000 fpm, impact would have occurred around 2 seconds later, so make that 185kts at t-12 seconds rather than t-10.
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